Now, more than eight years later, crucial questions remain about what really happen here.

And tonight, in his first network television interview, that nurse offers new details, and new information -- including his answer to the most perplexing question of all. Is he a killer, a hero, or a victim himself?

Long before the world wondered anything about Ted Maher, he was a young man who needed the Army to pay for college.

Ted did well in the military, from Ft. Bragg to the Special Forces to the Green Berets.

Sara James, Dateline NBC: That's the elite.

Ted Maher: Yes, it is. You really don't have to prove yourself to anyone else after that.

Ted had been a medic in the Special Forces, and after the Army decided to return to school to become a nurse.

That's where he met his wife Heidi.

After graduation Ted took a job working with premature infants in neo-natal intensive care.

Ted had one child from a previous marriage. He and Heidi had two more.

Ted Maher: In fact, the two littlest children, personally delivered.

Sara James, Dateline NBC: What was that like for you?

Ted Maher: It was probably one of the most special moments in my life.

It was a far less remarkable moment, however, that would set Ted’s quiet life on a dramatic new course.

One day at work at the hospital, he found a camera that belonged to the parents of newborn twins who'd been discharged. He mailed it back with a note wishing them well.

Sara James, Dateline NBC: And so by being a Good Samaritan, suddenly you came to the attention of the Safras?

Ted Maher: Correct. The daughter of Mrs. Safra was the godmother of these two twins.

Sara James, Dateline NBC: Had you heard of Edmond Safra ?

Ted Maher: Never.

Sara James, Dateline NBC: Seen his name in the papers?

Ted Maher: Never.

Sara James, Dateline NBC: Knew that he was a big banking magnet?

Ted Maher: No.

Sara James, Dateline NBC: Indeed -- a billionaire?

Ted Maher: No.

Sara James, Dateline NBC: None of that?

Ted Maher: No.

Edmond Safra, head of Republic National Bank, was not exactly a household name in America, except perhaps among those in the know on Wall Street.

Maria Bartiromo, CNBC: He was doing business with incredibly wealthy individuals in dangerous parts of the world, and he knew that this was highly, highly confidential business. So, he was very secretive.

Edmond came from a long line of Safra bankers, a family of Sephardic Jews who left the Middle East and catered primarily to wealthy, Jewish communities around the globe.

Reporter Bryan Burroughs wrote a book about Edmond Safra.

Burroughs: The hallmark of Safra's banks was always discretion. That, you know, you could tell your secrets to one of Edmond’s men and the secret police wouldn't barge down your door that night.

But Safra's Trusted bank became embroiled in a legendary business scandal that threatened to tarnish his image.

In 1983, Safra briefly merged his firm with American Express. When the merger didn't work out, rival executives at American Express spread unsubstantiated rumors that Safra was laundering money for organized crime.

The betrayal reinforced the banker's distrust of outsiders.

Bryan Burroughs: It's almost like he and his family had a gene for paranoia. Even before the American Express scandal broke, they saw boogiemen behind every bush.

Edmond Safra's reported paranoia increased later in life with the onset of Parkinson’s disease.

With his vast fortune, the ailing banker could afford a staff of nurses for round the clock care.

There was a position open and the Safra's offered Ted a job. Impressed with his good deed, they'd also found his experience appealing: a qualified nurse who'd also been a military man, someone who could be counted on to watch the boss's back..

To Ted, it sounded like a dream job. The pay was more than $200,000 dollars a year.

The job came with another perk: an all-expenses paid opportunity to see the world from the vantage of a billionaire. Ted would be caring for Mr. Safra when he was in New York, and, for months at a time, in the south of France where the Safra's owned a penthouse in the heart of Monte Carlo.

Ted would be separated from his family for long stretches, but the offer was too good to refuse.

Sara James, Dateline NBC: You felt lucky.

Ted Maher: I felt blessed. I mean, it wasn't a matter of being lucky. It was almost like a blessing.

It was the summer of 1999. Ted Maher packed his bags and headed to Monte Carlo with his dream job waiting.

Monte Carlo, Monaco, is an elite showcase for the rich and famous, and as a personal nurse to billionaire Edmond Safra, Ted Maher had been granted a back-stage pass.

Ted Maher: Every place that I ever visited, his banks, his offices -- were beyond your wildest dreams.

Sara James, Dateline NBC: This was like working for a king.

Ted Maher: Yes, it was.

Safra's formal estate in the south of France was it fact a castle that once belonged to a Belgian monarch.

His apartment in the center of Monaco was a sprawling penthouse on the top two floors of his bank building.

Ted Maher: It was beyond any description. So lavish, so beautiful.

Around the time Ted Maher began working for Edmond Safra, the banker -- who was 67 years old and suffered from Parkinson's disease -- was eyeing retirement and planning to make Monaco his permanent home.

As the banker's Parkinson’s disease worsened, and he prepared to cash out his business, some observers say the family affairs were increasingly controlled by his wife Lily.

Bryan Burrough: It is fair to say that all of the people around him knew not to step on the wrong side of Lily.

Once-widowed and twice-divorced, Lily didn't exactly fit in with the conservative Safra clan. By the late nineties, there was a well-known rift among the Safra brothers.

Boaz Bismuth: The cousin of Mr. Safra, he told me that one of the reasons why the family relation was so bad is Lily, the wife of Mr. Safra. That she drove him out of the family.

Whatever family turmoil was brewing behind the scenes, Ted says he enjoyed taking care of Mr. Safra. The job was much less hectic than the hospital work he was used to. In fact, on some nights it was a challenge to stay awake.

Ted Maher: I had heard of people being fired for falling asleep. So there was a different kind of stress.

Sara James, Dateline NBC: This was the stress of working for a billionaire?

Ted Maher: Correct.

Far from home, Ted says he bonded with one co-worker in particular -- a nurse from New Jersey named Vivian Torrente.

Vivian's daughter Genevieve was 19 when her mother went to work for the Safras.

Genevieve Torrente: She just told me she got this great job, it pays well, she gets to travel. It's great and I get to visit wherever she goes.

Ted Maher: She was like a mother figure to me. She was a very, very nice nurse.

But there was tension, Ted says, between him and the head nurse. They didn't get along.

And Ted missed his wife and kids back in New York.

Sara James, Dateline NBC: You were away from your family. You were working long hours. There must have been part of you that got sick of it.

Ted Maher: Yeah, but you know, I knew the end would justify the means. I was there for my family.

Then in November of 1999, two weeks before the fateful night that would change everything, Ted says he got some wonderful news. The probationary period of his employment was over and he was put on permanent staff.

What's more, he says, he began making plans for his family to come live with him in Monaco.

Ted Maher: I was given full benefits as far as health for my family. And I just couldn't believe it, you know, that, you know, it was like the Holy Grail.

Two weeks later, Ted went to work on the night of Dec. 2.

He was sharing the overnight shift with fellow nurse, Vivian Torrente, taking turns administering medication and sitting by the billionaire's bedside as he slept.

By all outward appearances it seemed like any other night.

But what came next, and the version of events you are about to hear -- Ted’s version -- would be debated, dissected and scrutinized from that night to this very day.

Take a look at the layout of the penthouse. On the top floor, the nursing station here.

Next to that, an exercise room that led into Safra's bedroom.

Through another door was a large bathroom and dressing area.

Around 4:30 in the morning, Vivian was with Safra in the bedroom, while Ted was in the nursing station, trying not to fall asleep on the job.

Ted Maher: I routinely went into Mr. Safra's gym and I grabbed a 10 kilo barbell that I brought into the

Ted says he was sitting here at a desk in the nursing station when out of nowhere, he was attacked.

Hit on the head from behind.

Ted Maher: I went down, I was assaulted from behind so I went down. I was dazed and as I went down, I realized something really bad's going to happen.

The former Green Beret says he sprang into action. Lurching up with the barbell in his hand, he saw two masked men.

With the weight, he knocked one of them to the floor.

Ted Maher: The second man pulled out a knife. And they grabbed a-hold of my leg, pulling me towards them as I was trying to get away from them. And they took the knife and I was cut on my left calf here, on the left calf. And I turned and I was cut on my right side with this knife. And then I turned again, trying to get away, and I was stabbed in the middle. And at that point, I went unconscious.

Ted believes he was only out for a few minutes. When he came to, he says the masked men were nowhere to be seen.

He rushed to tell the other nurse on duty that the apartment had been broken into.

Ted Maher: She said, "My God, Ted, you're bleeding." I said, "Vivian, there are two people here. "Take Mr. Safra, go into the bathroom."

Safra, who was obsessed with security, had equipped his bathroom with steel reinforced doors, turning it into a panic room for an emergency just like this.

Ted Maher: I gave her my cellular phone that I had. I said, "Here, you can call help. I'm going to go down and get medical help for myself.” Otherwise I was going to die.

With Safra and Vivian locked in the secure bathroom, Ted stumbled down to the bank lobby, where a security guard called police.

Within minutes he was in an ambulance on his way to Princess Grace Hospital, thinking the worst was over.

Ted Maher: I’m going to make it. I'm going to make it. I'm going to make it. I did it and everyone's going to be OK.

Sara James, Dateline NBC: What do you mean I did it?

Ted Maher: I stopped these people from killing Mr. Safra.

But it soon would become abundantly clear that Ted Maher’s actions inside the penthouse that night did not lead to the happy ending he might have envisioned. Far from it.

By the early morning hours of Dec. 3, Ted Maher was in the hospital being treated for stab wounds, while the men who'd attacked him inside billionaire Edmond Safra's penthouse were apparently at-large in Monte Carlo.

In New York, Ted’s wife Heidi got a call from her sister-in-law, who was watching the news.

Heidi Maher: She called me up and her first words to me were “What's the name of Ted’s boss?”

(TV news broadcast)

WNBC news: "Safra founded Republic National Bank of New York..."

The story and pictures being broadcast around the world were startling. Safra's glorious penthouse was in flames.

(TV news broadcast)

CNBC- "two men armed with knives broke into Safra's apartment..."

News reports said Edmond Safra and one of his nurses had survived the armed attack, but died later from smoke inhalation in a fire set by the intruders.

Safra's wife Lily managed to escape by climbing out a window.

Ted was in the hospital recovering when he learned that his billionaire boss and co-worker Vivian Torrente had died.

Boaz Bismuth: It's a huge amount of time. You can go from Paris to London in such a time.

But where were all those highly trained bodyguards?

Ironically, the Safras had felt safe enough in Monaco to let the entire security staff sleep at the Safra estate 10 miles away.

When Safra's chief of security did arrive, he tried to charge upstairs and save his boss, but the police put him in handcuffs, thinking he was part of the plot.

Boaz Bismuth: They arrested him, they prevented him from going inside.

A picture of an inept, bungling Monaco police department was beginning to take shape.

The story now had the potential to be a huge source of embarrassment for the principality which banked on its reputation as a safe haven for the rich and royal.

With each new detail, the story of the banker and his masked assassins became increasingly bizarre.

But according to authorities here, there was a reason why the early news reports read like a Hollywood screenplay: the tale of the armed intruders was complete and utter fiction.

Within days of the attack, authorities announced a brand new theory of the crime, and it had nothing to do with the Safra family feud, the PLO or Russian mob.

According to authorities, there had been no intruders -- Ted Maher had done the whole thing himself. Ted's knife wounds -- superficial, and self- inflicted. The fire -- set by Ted. The motive? Ted was afraid of losing his dream job and wanted to curry favor by staging false heroics.

Boaz Bismuth: He wanted to impress his boss, he was in very bad terms with the main nurse. Two reasons.

Ted repeated that story numerous times to authorities investigating the case.

He even walked police through his actions, recreating the crime inside the burned out penthouse.

And yet, whispers of a larger conspiracy lingered.

Bismuth: If you talk to my people in the Jewish community in Monaco and some of the body guards, they think that the case was closed too quickly without really checking what happened.

Ted Maher had spent more than three years in jail when his case came to trial in 2002.

In court, Ted’s lawyers didn't deny that he'd faked the attack and started the fire, but argued that he'd never meant to harm anyone -- least of all Edmond Safra, whom he'd been desperately trying to impress.

Ted himself called the entire affair a "terrible accident."

In the end, the story that had started out as an international whodunit concluded with a swift conviction and a 10-year sentence for deadly arson.

But that decisive ending was actually just the beginning, Ted Maher says today.

For him, the conviction was the start of a long, uphill struggle to clear his name.

Ted Maher: That's why I am here before you today, to tell the truth. And I waited almost eight years of my life. Can you imagine not being able to speak to your family and not being able to tell your family the truth?

The truth, Ted says, has nothing to do with the confession he signed. That story, he says, was made up by police while he was recovering in the hospital.

Ted Maher: They said you did this, you killed Vivian Torrente, you have killed Mr. Safra and I said no I haven’t and they continued to grill me. You know, making accusations about me that I was a murderer, an assassin. That I had ulterior motives.

Sara James, Dateline NBC: But somewhere in all of this, a confession took shape.

Ted Maher: You want to call that a confession?

Ted says that police presented him with a document written in French -- a language he can't read-- and told him to sign, or else.

Ted Maher: I did not even know what I was signing. I did not know what this document was until after it was translated.

Ted says he signed that so-called confession because the Monaco authorities were holding his wife Heidi. She'd jumped on a plane to see him, leaving their three children back in New York.

Ted Maher: The French police came up and said "you will sign this or your wife will not leave the country.”

Back in 2000, Ted’s wife told Dateline that while her husband was in the hospital, she was subjected to a three-day police interrogation.

Heidi Maher: I answered anything they wanted, provided anything they wanted to the police in the hopes of seeing him. I just needed to see him ... to make sure he was OK.

Monaco authorities tell Dateline that Ted Maher always had access to an English translator.

But as evidence that the French confession was made up, Ted insists that the alleged motive is completely illogical. He had no reason for false heroics. He'd just been put on permanent staff, his well-paying job was secure.

Ted Maher: I already have everything that I wanted in life, could possibly want in life. And I want to kill my employer? Or show myself as a hero? What's the purpose? I didn't have--

Sara James, Dateline NBC: You say it makes no sense.

Ted Maher: I don't have to say. It doesn't make any sense. There is no reason. There's no rationale for it.

But remember, during his trial Ted’s own lawyers admitted he'd faked the attack and started the fire.

Ted now claims that he went along with the story because his defense attorneys assured him that he'd get little jail time if appeared cooperative.

Ted Maher: I was told that "Don't worry, Ted. Go with this because if you don't, in the end, they're going to condemn you. And you're going to go to jail for a very long period of time. And you'll never see your family again."

Sara James, Dateline NBC: You're saying your Monaco lawyers instructed you to go along with the idea that you'd faked the stories of the intruders.

Ted Maher: Following this so called drafted confession, yes.

Sara James, Dateline NBC: Your lawyers instructed you to do this?

Ted Maher: Yes.

Ted's Monaco lawyers say they never suggested he should lie in court.

But now, eight years later, Ted’s version of events has changed again.

What really happened the night Edmond Safra died?

In the winter of 2003, Ted Maher had begun his 10-year prison sentence for killing banker Edmond Safra and a fellow nurse.

He'd confessed to staging an attack and setting a fire in the billionaire's penthouse.

But alone inside his Monaco cell, Ted felt like a man unjustly convicted.

Desperate and determined, he began plotting his escape -- and not through a court of appeals.

One January night, the former Green Beret made a run for it.

Ted Maher: And I sawed myself through seven layers of bars. And I was on my way to freedom.

Ted Maher: Didn't have a clue. Never prepared, didn't even have a clue. Never even thought about it.

Ted blames the slow response by the Monaco police and fire departments for letting that small trashcan fire grow into a deadly inferno.

A government report says firefighters were hampered by the very things Edmond Safra had installed to make his home secure: the steal shutters and bullet-proof glass. And says their slow response was partly due to Ted’s fake story about armed intruders.

But today Ted insists he was attacked that night--- and says the notion that he'd stab himself to look like a hero is utterly ridiculous.

Ted Maher: I don't think so.

Sara James, Dateline NBC: Why would you do it? Doesn't make sense.

Ted Maher: There's no motive there at all.

Sara James, Dateline NBC: Unless you're unstable.

Ted Maher: Yeah, unless you're unstable.

Sara James, Dateline NBC: Are you mentally unstable?

Ted Maher: I don't think I was unstable. No, absolutely not.

Ted Maher’s reversal re-opens the questions about those mysterious intruders. If they existed, who were they? And how did they penetrate the Safra apartment undetected?

Michael Griffith: I believed that what he was telling me was the truth.

Attorney Michael Griffith of South Hampton, N.Y., represents Americans imprisoned abroad. Most notably he was the defense lawyer in the sensational case that became the movie “Midnight Express."

Griffith got involved in Ted’s defense after he was contacted by Amnesty International.

Michael Griffith: He told me about the intruders. I told him that I could bring the Justice Department into this operation and possibly have the FBI contact the Monaco authorities to do a real investigation.

Sara James, Dateline NBC: You saw this as, "Hey, maybe he signed a confession. But who believes a confession if it's signed in a language he doesn't even speak?"

Michael Griffith: Sara, I stay up at night dreaming I’m going to get a case where a client signs a confession in a foreign language.

Griffith says he tried to convince Ted to publicly renounce that confession before his case went to trial.

But Ted was afraid he'd get more jail time if he changed his story, yet couldn't prove his version of events.

Griffith: I thought it was terrible. I thought it was disgraceful.

Sara James, Dateline NBC: Are you saying, then, that Ted Maher is not responsible for the death of Edmond Safra and Vivian Torrente?

Sara James, Dateline NBC: And to become an inferno that consumed a penthouse and took the life of Edmond Safra and his nurse.

Michael Griffith: Exactly. And the lawyers in the case permitted the confession to go in that Ted stabbed himself three times, which is ridiculous.

Griffith says that not only was Ted the victim of bad legal advice, but that the entire case against him was a sham designed to protect the state of Monaco.

Michael Griffith: Monaco presents this fiction that they're the safest place in the world. There was a rush to judgment. They wanted Monaco’s reputation of being safe and secure to be maintained.

Sara James, Dateline NBC: So, you feel like a sacrificial lamb.

Ted Maher: I was a sacrificial lamb for that country's image. There's no getting around that. It's so obvious.

Ted and his American lawyer say that not only was he railroaded in the investigation, but also that the trial was rigged from the start.

And last summer, a Monaco judge came forward with evidence to back them up. The judge, who approved Ted’s indictment, says he was part of a secret meeting where the prosecutor and one of Ted’s very own Monaco attorneys agreed in advance to fix the verdict and sentence.

The prosecutor on the case and Ted’s Monaco attorneys all say the trial wasn't fixed, and point out that Ted’s conviction was ultimately decided by a 6-person jury.

But there's one other lawyer who thinks the trial and conviction Ted Maher was an orchestrated sham.

Pompeyo Realuyo: It was a badly scripted play.

Sara James, Dateline NBC: Badly scripted play?

Pompeyo Realuyo: Yeah.

Attorney Pompeyo Realuyo is an international tax attorney who also handles high-profile pro-bono cases. He flew to Monaco to watch the sensational Safra trial on behalf of nurse Vivian Torrente’s family.

He thinks the case was rigged in order to downplay something else tragic he believes happened that night: that Edmond Safra -- terrified and paranoid -- forced his nurse to die with him.

Popeyo: Safra was guilty of involuntary homicide by preventing Vivian from escaping.

Torrente's autopsy report contains what could be evidence of a struggle, bruising around the neck --details her family says have never been fully investigated.

Genevieve Torrente: It obviously suggests that there was a struggle. That maybe she was trying to leave. But she was kept from leaving.

An attorney for Safra's widow Lily calls that "absurd" and suggests that the bruises might have come from Safra leaning on his nurse while being moved.

But to Ted Maher and his lawyer, that's just one of many unanswered questions from the early morning of Dec. 3, 1999.

Michael Griffith: Look, no investigation was ever done by the Monaco police, OK. Monaco police, if you're listening, do your investigation and maybe you'll find out what really happened.

What might a new investigation find? That assassins had in fact had penetrated that the Safra apartment that night? Or that Ted Maher’s story falls apart before their eyes....

Michael Griffith: This is something like a classic incompetence and cover up. And I don't know whether we'll ever get to the bottom of this.

The mystery of billionaire banker Edmond Safra and his nurse had to some added up to a muddle of half-truths and unproven accusations.

Boaz Bismuth: Everybody in this story believes what suits him.

Ted Maher believes that he was witness to an assassination attempt gone awry, but we had some more questions about his version of events.

Sara James, Dateline NBC: Can you help me understand a few more things. Let’s go back to the night in question.

Remember, Ted says he was abducted two days before the attack and told that a window shutter needed to be left open.

Sara James, Dateline NBC: What I don't understand about these guys is why tell you that they're going to attack?

Ted Maher: I didn't -- there was no telling me they were going to attack. I was told one thing specific. I was told to make sure that the valence was kept open.

Sara James, Dateline NBC: You're told that by guys who are wearing masks.

Ted Maher: Right.

Sara James, Dateline NBC: If that's not an indication that they're planning an attack, I don't know what is.

Ted Maher: Yeah, you're right. You're right.

Sara James, Dateline NBC: So, why tell a Green Beret? Why warn you?

Ted Maher: I don't know.

Sara James, Dateline NBC: You are the last person I would warn.

Ted Maher: I don't know. I don't know.

Sara James, Dateline NBC: And then, not only do they warn you, but then they come and they're just armed with knives.

Ted Maher: I’m sure that they had guns. I’m sure.

Sara James, Dateline NBC: But you didn't see any guns.

Ted Maher: I didn't see any. I mean, this whole incident. This thing didn't transpire over a five minute fight. I mean, this was happening in seconds, OK? Boom. I'm stabbed. I'm out unconscious. I wake. I come to. These people are I don't know where.

Ted believes the men who stabbed him and left him unconscious had come to murder Edmond Safra.

But why then did they flee before finishing the job?

Sara James, Dateline NBC: If this is an assassination attempt, as you say you suspect it was, why not assassinate him? He's in his bed. Who could be more defenseless?

Sara James, Dateline NBC: Because it's the middle of the night and you're -- it's easy to fall asleep.

Ted Maher: Right.

Sara James, Dateline NBC: But I don't understand. Because you know that that particular night--

Ted Maher: Something may happen. Something's--

Sara James, Dateline NBC: Something huge is going to happen. The valence is open. I mean, that's not a typical night. You're not going to have any trouble falling asleep that night.

Ted Maher: No. I mean--

Sara James, Dateline NBC: You're going to be on pins and needles.

Ted Maher: Yes, you're right. And I was. I mean, but, I mean, after 36 hours on without any sleep at all and being under that stress. By 4:30 in the morning I was exhausted.

Ted Maher, who was briefly hailed as a hero, then cast as the villain, says he's really been just a victim all along.

Sara James, Dateline NBC: Is there one other possibility though? That the Monaco police were incredibly inefficient. That the fire department was utterly incompetent. That your trial was a complete fraud. And that it is also true you concocted this. Is it possible both those things are true?

Ted Maher: No. Because I already explained several times before. I mean, there's no motive. I've been put on permanent staff. I don’t have to prove myself as a hero. There's no more pieces of the puzzle. What, after I’ve been given everything, I want to...

Sara James, Dateline NBC: But does the story of the intruders sound far-fetched even to you?

Ted Maher: I don’t know.

Ted's wife Heidi stood by him during his trial, but divorced him in 2006 and today has full custody of their children.

The penthouse in Monaco has been rebuilt, though Lily Safra, now in her seventies and one of the richest women in the world, spends most of her time in London -- far away from what was once their luxurious, safe haven.

Vivian Torrente’s daughter would like to move on as well.

Genevieve Torrente: Like, you want to believe that's the end of the story. But, you know, in the back of my head I always kind of felt that it's not the end of the story. It's not what really happened. Or -- and, like, you know, part of me thinks that I’ll never find out what happened.

Two lives are gone, an undeniable loss whatever version of the story you choose to believe.

Sara James, Dateline NBC: This is the question, really, Ted. Were you lying then or are you lying now?

Dateline wires the home of a volunteer, Jenny, from top to bottom with hidden cameras. Then she called repairmen to her house for a simple problem we created as a test with Jenny's pool. NBC's Chris Hansen reports.